These three terms get used loosely, and often incorrectly, in discussions about peptide therapy. The distinctions actually matter quite a bit for understanding both the legal status and the evidence behind any specific use.
FDA-Approved Use
This means the drug has gone through clinical trials specifically for that condition, and the FDA-approved label explicitly lists it as an indication. Semaglutide's approved uses include type 2 diabetes management and chronic weight management, each supported by its own dedicated trial program and each listed specifically on the drug's label.
Off-Label Use
Off-label means a licensed physician prescribes an FDA-approved drug for a use, dose, or population not specifically listed on its approved label. This is legal, common across medicine generally, and not inherently a red flag, physicians have discretion to prescribe based on clinical judgment and available evidence, even absent a formal FDA indication. However, the strength of evidence behind any specific off-label use can vary enormously, from substantial supporting research to very little at all.
Unapproved Use
This describes a substance, like BPC-157 or TB-500, that has no FDA-approved drug label at all, for any condition, prescribed by anyone. There's no approved indication for a physician to prescribe on- or off-label from, because no formal indication exists in the first place. Any use of these compounds happens entirely outside the FDA's drug approval framework, which is a fundamentally different category than off-label prescribing of an already-approved medication.
Why the Conflation Happens
Marketing and casual conversation often blur these categories, describing an unapproved research-chemical peptide as being used "off-label," which implies a level of regulatory grounding that doesn't actually exist. A physician can legitimately prescribe semaglutide off-label for a use outside its approved indications; there is no equivalent legitimate off-label pathway for a substance that was never approved as a drug to begin with.
Why This Distinction Is Worth Holding Onto
Knowing which of these three categories a specific use falls into is one of the fastest ways to evaluate a claim you encounter about any peptide. "Off-label" and "unapproved" get used almost interchangeably in casual peptide discussion, but they describe genuinely different regulatory and evidentiary situations, and collapsing that distinction makes it much easier to overestimate how much oversight and evidence actually stands behind a given use.
A Quick Way to Check Any Specific Claim
When you encounter a claim about a peptide's approval status, checking the FDA's official Orange Book listing for approved drugs, or ClinicalTrials.gov for trial status discussed in this site's dedicated pipeline-tracking guide, takes only a couple of minutes and settles the question directly, rather than relying on how confidently a vendor or forum post happens to describe a compound's legitimacy.